Biological safety is a paramount concern in modern society. Testing for biological contamination in foods or other materials has become an important and sometimes mandatory requirement for developers and distributors of food products. Biological testing is also used to identify bacteria or other agents in laboratory samples such as blood samples taken from medical patients, laboratory samples developed for experimental purposes, and other types of biological samples. Various techniques and devices can be utilized to improve biological testing and to streamline and standardize the biological testing process.
In particular, a wide variety of biological growth media have been developed. As one example, biological growth media in the form of growth plates have been developed by 3M Company (hereafter “3M”) of St. Paul, Minn. Biological growth plates are sold by 3M under the trade name PETRIFILM plates. Biological growth plates can be utilized to facilitate the rapid growth and detection or enumeration of bacteria or other biological agents commonly associated with food contamination, including, for example, aerobic bacteria, E. coli, coliform, Enterobacteriaceae species, yeast, mold, Staphylococcus aureus, Listeria species, Campylobacter species, and other biological agents. The use of PETRIFILM plates, or other biological growth media, can simplify bacterial testing of food samples.
Biological growth media can be used to identify the presence of bacteria so that corrective measures can be performed (in the case of food testing) or proper diagnosis can be made (in the case of medical use). In other applications, biological growth media may be used to rapidly grow bacteria or other biological agents in laboratory samples, e.g., for experimental purposes.
Biological growth medium processing systems refer to systems used to process biological growth media, and read or count bacterial colonies, or the amount of a particular biological agent on or in a biological growth medium. For example, a food sample or laboratory sample can be placed on or in a biological growth medium, and then the medium can be inserted into an incubation chamber. After incubation, the biological growth medium can be introduced into the biological reader, which generates one or more images of the biological growth medium. The images can then be analyzed, e.g., via a computer, for automated enumeration of bacterial growth. In this way, biological growth medium processing systems automate the detection and enumeration of bacteria or other biological agents on a biological growth medium, and thereby improve the biological testing process by reducing human error.